This invention relates generally to expandable rooms, and more particularly to room structures that are moveable between retracted and expanded positions. The invention particularly relates to vehicles such as recreational vehicles that are provided with one or more expandable room or room portions that are capable of moving from a retracted position to an expanded position to provide additional internal space. Typically, one portion of the room is nested within a portion of an existing room of the vehicle that remains fixed. Although similar structures can be used effectively in static structures, the description and disclosure focuses primarily on such rooms that are used in vehicles.
As is well known to those skilled in the art, when a recreational vehicle equipped with an expandable room is in motion, the room typically remains in a retracted position. This is necessary in order for the vehicle to move over the road and remain within vehicle width limitations. However, when the vehicle is stopped for a period of time, it is often desirable to increase the size of the internal accommodations, and in order to do so the user will cause the moveable portion of the room to move outwardly to an expanded position.
The prior art discloses various structures for moving the room from a retracted to an expanded position and returning the room to the retracted position where it is typically held in place. Because such rooms, especially those used in vehicles, are exposed to a variety of weather conditions, it is necessary to provide a proper, weather-tight seal between the moveable room structure and the fixed structure from which the room expands and retracts. These seals are subjected to considerable force and must seal against movement in both a horizontal and a vertical direction since there can be slight movement between the expandable room and the fixed structure even when the room is retracted and held in a retracted position. The expandable rooms are typically quite large and heavy and exert considerable force and can move vertically even when in the retracted position due to forces that occur when the vehicle is driven over the road. In addition, some of the mechanisms for moving the room from a retracted to an expanded position move the room downwardly as it is expanded so that the floor of the expanded room will be level with the floor of the fixed structure. This is commonly referred to as the ‘level out’ feature. As the expandable room is retracted or expanded, there is some vertical movement between the expandable room and the fixed structure of the vehicle as the moveable room engages the seals between the fixed structure and the moveable room structure.
It is therefore the principle object of the invention to provide an improved seal between the expandable room and the fixed structure under all anticipated conditions and forces that may be exerted between the structures.